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What is Stress, and What Does it Do?

Some definitions of stress

  • "Stress occurs when pressure exceeds your perceived ability to cope". (Stephen Palmer 1999).
  • "Stress arises when individuals perceive that they cannot adequately cope with the demands being made on them or with threats to their well-being". (R.S.Lazarus 1978).
  • "Stress is the psychological, physiological and behavioural response by an individual when they perceive a lack of equilibrium between the demands placed on them and their ability to meet these demands, which, over a period of time, leads to ill health". (Stephen Palmer 1998).

The fight or flight response (named by Cannon and Selye in the 1930s) is a pattern of physiological responses that prepare the organism (that's us) to emergency. When faced with perceived threat our body changes its internal balance accordingly. It is this automatic response that we call 'stress'. The fact that modern problems do not require such means is exactly the setting of stress-related problems (Atkinson et al, 1996; Lev, 1987).

The primitive survival mechanism known as the 'Fight/Flight/Freeze' response is built in to every human. It responds to fear/danger from everything from life threatening situations to the alarm going off in the morning. Every human has a habitual response to stress that is either learned or genetically implanted. In a real life or death situation almost all of this response will be trigger by survival to help you to fight off or flee this danger, or keep very still.

Since awareness is half the battle in controlling stress, you must learn to be aware of how you respond to stress. Remember, you have a unique response. It may include:

  1. Increased heart rate. This pumps blood around the body to get oxygen and sugars to the cells that you will need to use to survive. Symptoms that can be associated with this stress response might include: rapid or irregular heartbeats.
  2. Breathing usually becomes more rapid, to get more oxygen into the body. Symptoms that can be associated with this stress response might include: hyperventilation and some forms of asthma.
  3. Stress hormones are released. Adrenaline is released by the adrenal glands. This hormone helps to maintain increased heart rates and will tell the liver to release stored sugar for energy to the body. Other stress hormones do other thing. Noradrenaline is associated with anger and will raise blood pressure for most people. Symptoms that can be associated with this stress response might include: high blood pressure, panic or anxiety.
  4. Blood pressure can go up, triggered by released stress hormones. Symptoms that can be associated with this stress response might include: high blood pressure.
  5. Muscles that you would use to fight or flee often become very tight until released by relaxation, massage, stretching, or exercise. This is one of the most common responses to stress and has lead to everyday expressions like: 'uptight', 'Pain in the neck' (and other places.) Symptoms that can be associated with this stress response might include: tension headaches, tight jaw, neck / shoulder pain / tension, back pain, insomnia (including trouble getting to sleep, staying asleep, or not feeling rested after sleeping), fatigue, loss of concentration.
  6. Changes in blood flow / circulation. Blood is directed toward the brain and major muscles for survival. Blood is directed away from surface of skin in hands and feet (for survival a primitive response so you do not bleed to death if you get cut running away or fighting for your life.) Blood is directed away from digestive organ and reproductive organ because for survival it becomes a low priority to digest food or keep the species alive if you are threatened. Symptoms that can be associated with this stress response might include: high blood pressure, cold hands and feet, upset stomach, migraine headaches, pre-ulcerous / ulcerous conditions, increased colitis, sometimes constipation, and 70% of sexual dysfunction in both men and women can be linked to this stress response.
  7. All of your senses are heightened are survival vigilance. You are more sensitive to noise (ringing telephones or door bells), to light, to smells, even to increased sensitivity to touch. Your neo-cortex (the thinking part of your new brain) shuts down and the survival mechanisms in the middle and lower more primitive parts of the brain take over, so you react to things and do not think things through as well. Basic emotions: fear, anger, sadness, and joy (nervous laughter) take over from complicated, sophisticated higher function emotions. Symptoms that can be associated with this stress response might include: emotional irritability, substance abuse to escape stress through self-medication, anxiety, depression, poor impulse control, poor problem solving and reduced communication abilities.
  8. You perspire / sweat to cool the body's increased metabolism down.
  9. Imbalances in normal hormone levels. Longer term, unresolved stress can affect the immune system which is normally there to fight off infections and promote healing. Symptoms that can be associated with this stress response might include: frequent colds or flu and other infections.

Everyone holds their tension in one or more of these systems. You need to identify which systems respond when you get stressed and then learn to release this physical tension. It takes time and motivated practice to learn to let go but the results in enhanced quality of life and increased productivity are worth the effort. (Stress education centre).

If the person perceives that the threatening situation has passed then the parasympathetic nervous system helps to restore the person to a state of equilibrium. However, for many people they perceive everyday of their life as stressful. Unfortunately, the prolonged effect of the stress response is that the body's immune system is lowered and blood pressure is raised which may lead to essential hypertension and headaches. The adrenal gland may malfunction which can result in tiredness with the muscles feeling weak; digestive difficulties with a craving for sweet, starchy food; dizziness; and disturbances of sleep.

Below are some of the symptoms of stress. Please note that these symptoms can also occur with a range of medical or psychological disorders. When in doubt, do consult your doctor or consultant. (Palmer, S. 2000).

Responses to stress (Palmer and Dryden, 1995)


  • Alcohol / drug abuse
  • Avoidance / phobias
  • Sleep disturbances / insomnia
  • Increased nicotine / caffeine intake
  • Restlessness
  • Loss of appetite / overeating
  • Anorexia, bulimia
  • Aggression / irritability
  • Poor driving
  • Accident proneness
  • Impaired speech / voice tremor
  • Poor time management
  • Compulsive behaviour
  • Checking rituals
  • Tics, spasms
  • Nervous cough
  • Low productivity
  • Withdrawing form relationships
  • Clenched fists
  • Teeth grinding
  • Type A behaviour e.g. talking / walking / eating faster;competitive; hostile;
  • Increased absenteeism
  • Decreased / increased sexual activity
  • Eat / walk / talk faster
  • Sulking behaviour
  • Frequent crying
  • Unkempt appearance
  • Poor eye contact.

Affect (Emotions)

  • Anxiety
  • Depression
  • Anger
  • Guilt
  • Hurt
  • Morbid jealousy
  • Shame / embarrassment
  • Suicidal feelings


  • Tension
  • Headaches
  • Palpitations
  • Rapid heart beat
  • Nausea
  • Tremors / inner tremors
  • Aches / pains
  • Dizziness / feeling faint
  • Indigestion
  • Premature ejaculation / erectile dysfunction
  • Vaginismus / psychogenic dyspareunia
  • Limited sensual and sexual awareness
  • Butterflies in stomach
  • Spasms in stomach
  • Numbness
  • Dry mouth
  • Cold sweat
  • Clammy hands
  • Abdominal cramps
  • Sensory flashbacks Pain


  • Helplessness
  • Isolation / being alone
  • Losing control
  • Accidents / injury
  • Failure
  • Humiliation / shame / embarrassment
  • Self and / or others dying / suicide
  • Physical / sexual abuse
  • Nightmares / distressing recurring dreams
  • Visual flashbacks
  • Poor self-image


  • I must perform well
  • Life should not be unfair
  • Self / other-damning statements
  • Low frustration statements e.g. I can't stand it.
  • I must be in control
  • It's awful, terrible, horrible, unbearable etc.
  • I must have what I want
  • I must obey 'my' moral code and rules
  • Others must approve of me
  • Cognitive distortions e.g. all or nothing thinking


  • Passive / aggressive in relationships
  • Timid / unassertive
  • Loner
  • No friends
  • Competitive
  • Put others' needs before own
  • Sycophantic behaviour
  • Withdrawn
  • Makes friends easily / with difficulty
  • Suspicious / secretive
  • Manipulative tendencies
  • Gossiping

Drugs / Biology

  • Use of: drugs, stimulants, alcohol, tranquillizer, hallucinogens
  • Diarrhoea / constipation / flatulence
  • Frequent urination
  • Allergies / skin rash
  • High blood pressure / coronary heart disease (angina / heart attack)
  • Epilepsy
  • Dry skin
  • Chronic fatigue / exhaustion / burn-out
  • Cancer
  • Diabetes
  • Rheumatoid arthritis
  • Asthma
  • Flu / common cold
  • Lowered immune system
  • Poor nutrition, exercise and recreation
  • Organic problems
  • Biologically based mental disorders

Reference Palmer, S. and Dryden, W. (1995)